prometheus/storage/series.go

323 lines
8.5 KiB
Go

// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package storage
import (
"math"
"sort"
"github.com/prometheus/prometheus/pkg/histogram"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/tsdb/chunks"
"github.com/prometheus/prometheus/tsdb/tsdbutil"
)
type SeriesEntry struct {
Lset labels.Labels
SampleIteratorFn func() chunkenc.Iterator
}
func (s *SeriesEntry) Labels() labels.Labels { return s.Lset }
func (s *SeriesEntry) Iterator() chunkenc.Iterator { return s.SampleIteratorFn() }
type ChunkSeriesEntry struct {
Lset labels.Labels
ChunkIteratorFn func() chunks.Iterator
}
func (s *ChunkSeriesEntry) Labels() labels.Labels { return s.Lset }
func (s *ChunkSeriesEntry) Iterator() chunks.Iterator { return s.ChunkIteratorFn() }
// NewListSeries returns series entry with iterator that allows to iterate over provided samples.
func NewListSeries(lset labels.Labels, s []tsdbutil.Sample) *SeriesEntry {
return &SeriesEntry{
Lset: lset,
SampleIteratorFn: func() chunkenc.Iterator {
return NewListSeriesIterator(samples(s))
},
}
}
// NewListChunkSeriesFromSamples returns chunk series entry that allows to iterate over provided samples.
// NOTE: It uses inefficient chunks encoding implementation, not caring about chunk size.
func NewListChunkSeriesFromSamples(lset labels.Labels, samples ...[]tsdbutil.Sample) *ChunkSeriesEntry {
return &ChunkSeriesEntry{
Lset: lset,
ChunkIteratorFn: func() chunks.Iterator {
chks := make([]chunks.Meta, 0, len(samples))
for _, s := range samples {
chks = append(chks, tsdbutil.ChunkFromSamples(s))
}
return NewListChunkSeriesIterator(chks...)
},
}
}
type listSeriesIterator struct {
samples Samples
idx int
}
type samples []tsdbutil.Sample
func (s samples) Get(i int) tsdbutil.Sample { return s[i] }
func (s samples) Len() int { return len(s) }
// Samples interface allows to work on arrays of types that are compatible with tsdbutil.Sample.
type Samples interface {
Get(i int) tsdbutil.Sample
Len() int
}
// NewListSeriesIterator returns listSeriesIterator that allows to iterate over provided samples.
func NewListSeriesIterator(samples Samples) chunkenc.Iterator {
return &listSeriesIterator{samples: samples, idx: -1}
}
func (it *listSeriesIterator) At() (int64, float64) {
s := it.samples.Get(it.idx)
return s.T(), s.V()
}
func (it *listSeriesIterator) AtHistogram() (int64, histogram.SparseHistogram) {
return 0, histogram.SparseHistogram{}
}
func (it *listSeriesIterator) ChunkEncoding() chunkenc.Encoding {
return chunkenc.EncXOR
}
func (it *listSeriesIterator) Next() bool {
it.idx++
return it.idx < it.samples.Len()
}
func (it *listSeriesIterator) Seek(t int64) bool {
if it.idx == -1 {
it.idx = 0
}
// Do binary search between current position and end.
it.idx = sort.Search(it.samples.Len()-it.idx, func(i int) bool {
s := it.samples.Get(i + it.idx)
return s.T() >= t
})
return it.idx < it.samples.Len()
}
func (it *listSeriesIterator) Err() error { return nil }
type listChunkSeriesIterator struct {
chks []chunks.Meta
idx int
}
// NewListChunkSeriesIterator returns listChunkSeriesIterator that allows to iterate over provided chunks.
func NewListChunkSeriesIterator(chks ...chunks.Meta) chunks.Iterator {
return &listChunkSeriesIterator{chks: chks, idx: -1}
}
func (it *listChunkSeriesIterator) At() chunks.Meta {
return it.chks[it.idx]
}
func (it *listChunkSeriesIterator) Next() bool {
it.idx++
return it.idx < len(it.chks)
}
func (it *listChunkSeriesIterator) Err() error { return nil }
type chunkSetToSeriesSet struct {
ChunkSeriesSet
chkIterErr error
sameSeriesChunks []Series
}
// NewSeriesSetFromChunkSeriesSet converts ChunkSeriesSet to SeriesSet by decoding chunks one by one.
func NewSeriesSetFromChunkSeriesSet(chk ChunkSeriesSet) SeriesSet {
return &chunkSetToSeriesSet{ChunkSeriesSet: chk}
}
func (c *chunkSetToSeriesSet) Next() bool {
if c.Err() != nil || !c.ChunkSeriesSet.Next() {
return false
}
iter := c.ChunkSeriesSet.At().Iterator()
c.sameSeriesChunks = c.sameSeriesChunks[:0]
for iter.Next() {
c.sameSeriesChunks = append(
c.sameSeriesChunks,
newChunkToSeriesDecoder(c.ChunkSeriesSet.At().Labels(), iter.At()),
)
}
if iter.Err() != nil {
c.chkIterErr = iter.Err()
return false
}
return true
}
func (c *chunkSetToSeriesSet) At() Series {
// Series composed of same chunks for the same series.
return ChainedSeriesMerge(c.sameSeriesChunks...)
}
func (c *chunkSetToSeriesSet) Err() error {
if c.chkIterErr != nil {
return c.chkIterErr
}
return c.ChunkSeriesSet.Err()
}
func newChunkToSeriesDecoder(labels labels.Labels, chk chunks.Meta) Series {
return &SeriesEntry{
Lset: labels,
SampleIteratorFn: func() chunkenc.Iterator {
// TODO(bwplotka): Can we provide any chunkenc buffer?
return chk.Chunk.Iterator(nil)
},
}
}
type seriesSetToChunkSet struct {
SeriesSet
}
// NewSeriesSetToChunkSet converts SeriesSet to ChunkSeriesSet by encoding chunks from samples.
func NewSeriesSetToChunkSet(chk SeriesSet) ChunkSeriesSet {
return &seriesSetToChunkSet{SeriesSet: chk}
}
func (c *seriesSetToChunkSet) Next() bool {
if c.Err() != nil || !c.SeriesSet.Next() {
return false
}
return true
}
func (c *seriesSetToChunkSet) At() ChunkSeries {
return NewSeriesToChunkEncoder(c.SeriesSet.At())
}
func (c *seriesSetToChunkSet) Err() error {
return c.SeriesSet.Err()
}
type seriesToChunkEncoder struct {
Series
}
const seriesToChunkEncoderSplit = 120
// NewSeriesToChunkEncoder encodes samples to chunks with 120 samples limit.
func NewSeriesToChunkEncoder(series Series) ChunkSeries {
return &seriesToChunkEncoder{series}
}
func (s *seriesToChunkEncoder) Iterator() chunks.Iterator {
chk := chunkenc.NewXORChunk()
app, err := chk.Appender()
if err != nil {
return errChunksIterator{err: err}
}
mint := int64(math.MaxInt64)
maxt := int64(math.MinInt64)
chks := []chunks.Meta{}
i := 0
seriesIter := s.Series.Iterator()
for seriesIter.Next() {
// Create a new chunk if too many samples in the current one.
if i >= seriesToChunkEncoderSplit {
chks = append(chks, chunks.Meta{
MinTime: mint,
MaxTime: maxt,
Chunk: chk,
})
chk = chunkenc.NewXORChunk()
app, err = chk.Appender()
if err != nil {
return errChunksIterator{err: err}
}
mint = int64(math.MaxInt64)
// maxt is immediately overwritten below which is why setting it here won't make a difference.
i = 0
}
t, v := seriesIter.At()
app.Append(t, v)
maxt = t
if mint == math.MaxInt64 {
mint = t
}
i++
}
if err := seriesIter.Err(); err != nil {
return errChunksIterator{err: err}
}
chks = append(chks, chunks.Meta{
MinTime: mint,
MaxTime: maxt,
Chunk: chk,
})
return NewListChunkSeriesIterator(chks...)
}
type errChunksIterator struct {
err error
}
func (e errChunksIterator) At() chunks.Meta { return chunks.Meta{} }
func (e errChunksIterator) Next() bool { return false }
func (e errChunksIterator) Err() error { return e.err }
// ExpandSamples iterates over all samples in the iterator, buffering all in slice.
// Optionally it takes samples constructor, useful when you want to compare sample slices with different
// sample implementations. if nil, sample type from this package will be used.
func ExpandSamples(iter chunkenc.Iterator, newSampleFn func(t int64, v float64) tsdbutil.Sample) ([]tsdbutil.Sample, error) {
if newSampleFn == nil {
newSampleFn = func(t int64, v float64) tsdbutil.Sample { return sample{t, v} }
}
var result []tsdbutil.Sample
for iter.Next() {
t, v := iter.At()
// NaNs can't be compared normally, so substitute for another value.
if math.IsNaN(v) {
v = -42
}
result = append(result, newSampleFn(t, v))
}
return result, iter.Err()
}
// ExpandChunks iterates over all chunks in the iterator, buffering all in slice.
func ExpandChunks(iter chunks.Iterator) ([]chunks.Meta, error) {
var result []chunks.Meta
for iter.Next() {
result = append(result, iter.At())
}
return result, iter.Err()
}